Image boundary extraction based on island model genetic algorithms for integrated circuit defect detection

The integrated circuit chip with high performance has a high sensitivity to the defects in manufacturing environments.When there are defects on a wafer,the defects may lead to the degradation of chip performance.It is necessary to design effective detection approaches for the defects in order to ensure the reliability of wafer.In this paper,a new method based on image boundary extraction is presented for the detection of defects on a wafer.The method uses island model genetic algorithms to perform the segmentation of wafer images,and gets the optimal threshold values.The island model genetic algorithm uses two distinct subpopulations,it is a coarse grain parallel model.The individuals migration can occur between the two subpopulations to share genetic materials.A lot of experimental results show that the defect detection method proposed in this paper can obtain the features of defects effectively.

Ant colony optimization approach for test scheduling of system on chip

It is necessary to perform the test of system on chip,the test scheduling determines the test start and finishing time of every core in the system on chip such that the overall test time is minimized.A new test scheduling approach based on chaotic ant colony algorithm is presented in this paper.The optimization model of test scheduling was studied,the model uses the information such as the scale of test sets of both cores and user defined logic.An approach based on chaotic ant colony algorithm was proposed to solve the optimization model of test scheduling.The test of signal integrity faults such as crosstalk were also investigated when performing the test scheduling.Experimental results on many circuits show that the proposed approach can be used to solve test scheduling problems.

A New Method for the Detections of Multiple Faults Using Binary Decision Diagrams

With the complexity of integrated circuits is continually increasing, a local defect in circuits may cause multiple faults. The behavior of a digital circuit with a multiple fault may significantly differ from that of a single fault. A new method for the detection of multiple faults in digital circuits is presented in this paper, the method is based on binary decision diagram （BDD）. First of all, the BDDs for the normal circuit and faulty circuit are built respectively. Secondly, a test BDD is obtained by the XOR operation of the BDDs corresponds to normal circuit and faulty circuit. In the test BDD, each input assignment that leads to the leaf node labeled 1 is a test vector of multiple faults. Therefore, the test set of multiple faults is generated by searching for the type of input assignments in the test BDD. Experimental results on some digital circuits show the feasibility of the approach presented in this paper.

Influence of Deposition Temperature on the Structure of Si_3N_4 Thin Film Prepared by MWECR-PECVD

The Si_3N_4 thin film is prepared by MWECR-PECVD at different deposition tem-perature and the structure of the Si_3N_4 thin film is investigated. The results indicate that thestructure of the Si_3N_4 thin film prepared at low deposition temperature is in the amorphousphase. However, when the deposition temperature increases to 280℃, the Si_3N_4 thin film changesto crystalline α-Si_3N_4. With a further increase of the deposition temperature, the grain of theSi_3N_4 thin film becomes more fine, uniform and flat. XRD analysis shows that the structure ofthe Si_3N_4 thin film prepared at 280℃ is of a crystalline structure.

Improvement of Optical Reactivity for Nano-TiO2 Film by Nitrogen ECR Plasma

Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance （ECR） plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma by optical emission spectroscopy （OES） was applied to the process of plasma modification. X-ray photoelectron spectroscopy （XPS） was used for analysis of the binding of element after plasma modification. It is shown that the surface modification was caused by excitated N. The injecting of N2 and N＋ leads to the increase in the dissociative interstitial state N in the films. The doped N makes for TiO2-xNx appearing in the TiO2 films. TiO2-xNx forms the impurity energy state in the TiO2 energy band gap and reduces the energy band gap. This is the main reason leading to the red shift of absorption edge.

A Neural Network Method for Reliability Optimizations of Complex Systems

The main task of system reliability design is to find the best layout of components to maximize reliability or to minimize cost. A reliability optimization approach using neural networks to identify the choice of components in series-parallel systems with multiple constraints is presented in this paper. The McCullochPittes neural network model is used in this approach. The design methods of the neural network construction and its energy function are described in detail. The optimal solutions of the reliability problem are obtained by minimizing the energy function of the neural networks. Simulation results show the reliability optimization approach using neural networks can find the optimal or near-optimal solutions for most of the problems in a relatively short time, it is a useful alternative for system reliability design of complex systems.

Propagation of shaped beam through uniaxially anisotropic chiral slab

A general solution is obtained to a canonical problem of the reflection and refraction of an arbitrary shaped beam by using a uniaxially anisotropic chiral slab.The reflected,internal as well as refracted shaped beams are expanded in terms of cylindrical vector wave functions,and the expansion coefficients are determined by using the boundary conditions and method of moments procedure.As two typical examples,the normalized field intensity distributions are evaluated for a fundamental Gaussian beam and Hermite-Gaussian beam,and some propagation properties,especially the negative refraction phenomenon,are discussed briefly.

Ion Density Distribution in an Inductively Coupled Plasma Chamber

The ion density distribution in the reaction chamber was diagnosed by a Langmuir probe. The rules of the ion density distribution were obtained under the pressures of 9 Pa, 13 Pa, 27 Pa and 53 Pa in the reaction chamber, different radio-frequency powers and different positions. The result indicates that the ion density decreases as the pressure increases, and increases as the power decreases. The ion density of axial position z =0 achieves 5.8×1010 on the center of coil under the power of 200 w and pressure of 9 Pa in the reaction chamber.

Microdomain atomic structure of Zr_(50)Pd_(40)Al_(10) metallic glasses and its formation mechanism

Zr-based Zr_50Pd_40Al_10 metallic glasses has not only crystalline phases of about 5 nm in diameter but also amorphous phases. In this work, the radial distribution functions(RDFs) of amorphous structure of Zr_50Pd_40Al_10 metallic glasses were firstly measured by electron diffraction, and then Reverse Monte Carlo(RMC) optimization accompanied by density functional theory(DFT) calculations. The amorphous structure has not only short-range order but also good medium-range order. In the RDFs of its amorphous structure, the first and the second peaks are located at 2.96 ? and 4.79 ?, respectively. Partial radical distribution functions(PRDFs) show that the contributions of the first and the second nearest-neighbor distances of various atom pairs to the G(r) peak values, and the first nearest-neighbor distances of Pd–Zr and Zr–Zr atom pairs are the sources of main G(r) peak values between 2? and 6?. The competition mechanism for generating the Pd_25Zr_55 Al_20 amorphous phase and the intermetallic crystalline phase Pd_11Zr_9 is associated with the differences of atomic radius, the proportion, and the melting point of different atoms, as well as the heat of mixing between atoms, leading to an equilibrium state of the two phases. Accordingly, a composite system with intertwined nanocrystals and amorphous phases is in turn formed, and improves the stability of the material.

Effects of Dummy Thermal Vias on Interconnect Delay and Power Dissipation of Very Large Scale Integration Circuits

The interconnect temperature of very large scale integration（VLSI） circuits keeps rising due to self-heating and substrate temperature, which can increase the delay and power dissipation of interconnect wires. The thermal vias are regarded as a promising method to improve the temperature performance of VLSI circuits. In this paper, the extra thermal vias were used to decrease the delay and power dissipation of interconnect wires of VLSI circuits. Two analytical models were presented for interconnect temperature, delay and power dissipation with adding extra dummy thermal vias. The influence of the number of thermal vias on the delay and power dissipation of interconnect wires was analyzed and the optimal via separation distance was investigated. The experimental results show that the adding extra dummy thermal vias can reduce the interconnect average temperature, maximum temperature, delay and power dissipation. Moreover, this method is also suitable for clock signal wires with a large root mean square current.

Strong chirality in twisted bilayerα-MoO_(3)

Chiral structures are promising in many applications,such as biological sensing and analytical chemistry,and have been extensively explored.In this paper,we theoretically investigate the chiral response of twisted bilayerα-MoO_(3).Firstly,the analytical formula for the transmissivity is derived when the structure is illuminated with circularly polarized plane waves.Furthermore,the results demonstrate that the twisted bilayerα-MoO_(3)can excite the strong chirality with the maximum circular dichroism(CD)of 0.89.In this case,the chirality is due to the simultaneous breaking the rotational symmetry and mirror symmetry,which originates from the relative rotation of twoα-MoO_(3)layers.To better understand the physical mechanism,the polarization conversion between the left-hand circular polarization(LCP)and right-hand circular polarization(RCP)waves is discussed as well.Moreover,it is found that the structure can maintain the strong chirality(CD>0.8)when the twisted angle varies from 69°to 80°,which effectively reduces the strictness in the requirement for rotation angle.In addition,the CD can be larger than 0.85 when the incidence angle of circularly polarized plane wave is less than 40°,implying that the chirality is robust against the angle of incidence.Our work not only provides an insight into chirality induced by the twisted bilayerα-MoO_(3),but also looks forward to applications in biolo gical sensing.

The analytical model for crosstalk noise of current-mode signaling in coupled RLC interconnects of VLSI circuits

With the continuous advancement of semiconductor technology, the interconnects crosstalk has had a great influence on the performances of VLSI circuits. To date, most of the research about the interconnects of VLSI circuits focus on the voltage-mode signaling （VMS） scheme while the current-mode signaling （CMS） scheme is rarely analyzed. First of all, an equivalent circuit model of two-line coupled interconnects is presented in this paper, which is applicable to both the CMS and VMS schemes. The coupling capacitive and mutual inductive are taken into account in the equivalent circuit model. Secondly, the output noise of CMS and VMS schemes are investigated in the paper according to the decoupling technique and A B CD parameter matrix approach at local level, intermediate level and global level, respectively. Moreover, the experimental results show that the CMS interconnects have lesser noise peak, noise width and noise amplitude than the VMS interconnects in the same cases, and the CMS scheme is especially suitable for the global interconnects communication of VLSI circuits. It is found that the results obtained by A B CD parameter matrix approach are in good accordance with the simulation results of the advanced design system.

Study on the fluorescence quenching of ZnO by graphene oxide

锌氧化物(ZnO ) microrod 数组被蒸汽阶段运输(VPT ) 在 Si 底层上综合在一个试管炉子的方法。获得的 ZnO microrods 被扫描电子显微镜学(SEM ) 和 X 光检查衍射(XRD ) 描绘。光致发光(PL ) 测量显示 ZnO microrods 有一强壮紫外(紫外) 排放在 ~ 集中了 391 nm 和在 ~ 集中的缺点相关的排出物 530 nm。与 graphene 氧化物在 microrods 以后是涂的(去) ，混合微观结构的 PL 紧张与 GO 的集中以一样的刺激条件，和 PL 紧张变化与赤裸的的相比被熄灭。熄灭机制的荧光也在这个工作被讨论。

Higgs and Single Top Associated Production at the LHC in the Left-Right Twin Higgs Model

In the framework of the left-right twin Higgs(LRTH) model, we study the Higgs boson and single top quark associated production at the LHC. We investigate the processes pp → thj, pp → thˉb and pp → th W at the 8(14) Te V LHC and find that the production cross sections of the three processes can be enhanced at different levels. Among them,the production cross section of the process pp → thˉb is enhanced significantly due to the contribution of the new particles predicted by the LRTH model.

Search for single production of vectorlike B-quarks at the LHC

New vectorlike quarks have been proposed in many scenarios of new physics beyond the Standard Model,which address the hierarchy problem and may be potentially discovered at the Large Hadron Collider(LHC).Based on a model-independent framework,we propose to search for the vectorlike B-quark(VLQ-B)and focus on resonant production via b-gluon fusion through chromomagnetic interactions.We then explore the possible signals of the VLQ-B through the B→tW decay mode at the 14 TeV LHC.After a rapid simulation of signal and background events,the 2σ excluded regions and the 5σdiscovery reach in the parameter plane of k_(B)-M_(B)are obtained at the LHC with an integrated luminosity of 300(3000)fb^(-1)in the dilepton final states.

Freeze-in dark matter in EDGES 21-cm signal

The first measurement of the temperature of the hydrogen 21-cm signal reported by EDGES strongly fa-vors the Coulomb-like interaction between freeze-in dark matter and baryon fluid.We investigate such dark matter in both the one-and two-component context with the light force carrier(s)essential for the Coulomb-like interaction being other than photons.Using a conversion of cross sections used by relevant experiments and Boltzmann equations to encode the effects of the dark matter-baryon interaction,we show that both cases are robustly excluded by the stringent stellar cooling bounds in the sub-GeV dark matter mass range.The exclusion of the one-component case applies to simplified freeze-in dark matter with the light force carrier as dark photons,gauged B-L,Le-Lμ,Le-Lτ,or axion-like particles,whereas the exclusion of the two-component case applies to simplified freeze-in dark matter with the two light force carriers as two axion-like particles coupled to standard model quarks and leptons.

R-Symmetric NMSSM

It is well known that the observed Higgs mass is more naturally explained in the next-to-minimal supersymmetric standard model(NMSSM)than in the minimal supersymmetric standard model.Without any violation of this success,there are variants of the NMSSM that can lead to new phenomenologies.In this study,we propose a new variant of the NMSSM by imposing an unbroken R symmetry.We first identify the minimal structure of such a scenario from the perspective of both simplicity and viability,then compare the model predictions to current experimental limits,and finally highlight the main features that differ from those of well-known scenarios.

Detecting the micro-defects in the GaAs materials by time resolved emissions

The GaAs material is a major semiconductor material,and it has high electron transfer rate and direct transition energy band structure.The devices and integrated circuits fabricated on the GaAs substrates have a lot of advantages such as high speed information processing.Small perturbations in the manufacturing of GaAs materials can lead to defects.The defects in the GaAs materials can degrade the performance of materials.A new method is presented in this paper for detecting the micro-defects in GaAs materials by using time resolved emissions.In this method,the micro-defects in GaAs materials are detected by making use of the photon emission features of microdefects.The strength of the emitted photons from the micro-defects is increased by applying the electric current or the periodic pulse signals to GaAs materials.The singlephoton detector is used to detect the photon emissions of the micro-defects.The time resolved photon emissions and single-photon detection are used to record and compare the amounts of the emitted photons that come from the given regions of the normal GaAs materials and the defective GaAs materials.A lot of experimental results show that the micro-defects in the GaAs materials can be detected by using the method proposed in this paper.

Plasmon-enhanced ZnO whispering-gallery mode lasing

Collaborative enhancements from surface plasmons （SPs） and whispering-gallery modes （WGMs） can induce intense near-field effects with high spatial localization around the surface of a semiconducting material. One can construct a highly efficient hybrid microcavity using semiconducting materials through resonant coupling between SPs and WGMs. Hexagonal ZnO micro-/nanostructures, which have been employed as natural WGM microcavities for ultraviolet （UV） lasing, can be used as ideal platforms to construct such hybrid microcavities. Here, we comprehensively review the recent efforts for improving lasing performance by resonant coupling between SPs and WGMs. Traditional SPs originating from various metals as well as novel SPs originating from atomic layers such as graphene are considered. Moreover, we discuss the mechanism of light-matter interactions beyond the improvements in lasing performance.

A single-photon fault-detection method for nanocircuits that use GaN material

As the complexity of nanocircuits continues to increase,developing tests for them becomes more difficult.Failure analysis and the localization of internal test points within nanocircuits are already more difficult than for conventional integrated circuits.In this paper,a new method of testing for faults in nanocircuits is presented that uses single-photon detection to locate failed components(or failed signal lines)by utilizing the infrared photon emission characteristics of circuits.The emitted photons,which can carry information about circuit structure,can aid the understanding of circuit properties and locating faults.In this paper,in order to enhance the strength of emitted photons from circuit components,test vectors are designed for circuits’components or signal lines.These test vectors can cause components to produce signal transitions or switching behaviors according to their positions,thereby increasing the strength of the emitted photons.A multiple-valued decision diagram(MDD),in the form of a directed acrylic graph,is used to produce the test vectors.After an MDD corresponding to a circuit is constructed,the test vectors are generated by searching for specific paths in the MDD of that circuit.Experimental results show that many types of faults such as stuck-at faults,bridging faults,crosstalk faults,and others,can be detected with this method.